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          <th colspan="3" align="center">Opening a Transactional Environment and
            
            Store or Database
            
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            <h2 class="title" style="clear: both"><a id="envopen"></a>Opening a Transactional Environment and
            
            <span>Store or Database</span>
            
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      <p>
            To enable transactions for your environment, you must initialize the
            transactional subsystem. Note that doing this also initializes the
            logging subsystem. In addition, you must initialize the memory pool
            (in-memory cache). Frequently, but not always, you will also 
            initialize the locking subsystem.  
            
            
            
            <span>
                For example, to do this with the DPL:
            </span>
        </p>
      <pre class="programlisting">package persist.txn;
                                                                                                                                     
import com.sleepycat.db.DatabaseException;
import com.sleepycat.db.Environment;
import com.sleepycat.db.EnvironmentConfig;

import com.sleepycat.persist.EntityStore;
import com.sleepycat.persist.StoreConfig;

import java.io.File;
import java.io.FileNotFoundException;
                                                                                                                                     
...
                                                                                                                                     
Environment myEnv = null;
EntityStore myStore = null;
try {
    EnvironmentConfig myEnvConfig = new EnvironmentConfig();
    StoreConfig storeConfig = new StoreConfig();

    myEnvConfig.setInitializeCache(true);
    myEnvConfig.setInitializeLocking(true);
    myEnvConfig.setInitializeLogging(true);
    myEnvConfig.setTransactional(true);

    storeConfig.setTransactional(true);

    myEnv = new Environment(new File("/my/env/home"),
                              myEnvConfig);

    myStore = new EntityStore(myEnv, "EntityStore", storeConfig);

} catch (DatabaseException de) {
    // Exception handling goes here
} catch (FileNotFoundException fnfe) {
     // Exception handling goes here
}</pre>
      <p>
            And when using the base API:
    </p>
      <pre class="programlisting">package db.txn;
                                                                                                                                     
import com.sleepycat.db.DatabaseException;
import com.sleepycat.db.Environment;
import com.sleepycat.db.EnvironmentConfig;

import java.io.File;
import java.io.FileNotFoundException;
                                                                                                                                     
...
                                                                                                                                     
Environment myEnv = null;
try {
    EnvironmentConfig myEnvConfig = new EnvironmentConfig();
    myEnvConfig.setInitializeCache(true);
    myEnvConfig.setInitializeLocking(true);
    myEnvConfig.setInitializeLogging(true);
    myEnvConfig.setTransactional(true);

    myEnv = new Environment(new File("/my/env/home"),
                              myEnvConfig);

} catch (DatabaseException de) {
    // Exception handling goes here
} catch (FileNotFoundException fnfe) {
     // Exception handling goes here
}</pre>
      <p>
        You then can use the <tt class="classname">Environment</tt> handle to open
        your database(s) using <tt class="methodname">Environment.openDatabase()</tt>.
        Note that when you do this, you must set
                <tt class="methodname">DatabaseConfig.setTransactional()</tt>
        to <tt class="literal">true</tt>. Note that in effect this causes the
        database open to be transactional protected because it results in
        auto commit being used for the open (if a transaction is not explicitly
        used to protect the open).
        For example:
    </p>
      <pre class="programlisting">package db.txn;
                                                                                                                                     
<b class="userinput"><tt>import com.sleepycat.db.Database;
import com.sleepycat.db.DatabaseType;
import com.sleepycat.db.DatabaseConfig;</tt></b>
import com.sleepycat.db.DatabaseException;
import com.sleepycat.db.Environment;
import com.sleepycat.db.EnvironmentConfig;

import java.io.File;
import java.io.FileNotFoundException;
                                                                                                                                     
...
                                                                                                                                     
<b class="userinput"><tt>Database myDatabase = null;</tt></b>
Environment myEnv = null;
try {
    EnvironmentConfig myEnvConfig = new EnvironmentConfig();
    myEnvConfig.setInitializeCache(true);
    myEnvConfig.setInitializeLocking(true);
    myEnvConfig.setInitializeLogging(true);
    myEnvConfig.setTransactional(true);

    myEnv = new Environment(new File("/my/env/home"),
                              myEnvConfig);

    <b class="userinput"><tt>// Open the database.
    DatabaseConfig dbConfig = new DatabaseConfig();
    dbConfig.setTransactional(true);
    dbConfig.setType(DatabaseType.BTREE);
    myDatabase = myEnv.openDatabase(null,               // txn handle
                                    "sampleDatabase",   // db file name
                                    null,             // db name
                                    dbConfig);</tt></b>
} catch (DatabaseException de) {
    // Exception handling goes here
} catch (FileNotFoundException fnfe) {
    // Exception handling goes here
}</pre>
      <div class="note" style="margin-left: 0.5in; margin-right: 0.5in;">
        <h3 class="title">Note</h3>
        <p>
                Never close a database <span> or
                        store </span> that has active transactions. Make sure
            all transactions are resolved (either committed or aborted)
            before closing the database.
        </p>
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